#include "SimplexTemplateTagAssigner.hpp"

#include "EdgeSizeEvaluator.hpp"
#include "moab/Interface.hpp"
#include "RefinerTagManager.hpp"
#include "SimplexTemplateRefiner.hpp"

#include <vector>

#include <cmath>

namespace moab
{

using namespace std;

/// Construct a template tag assigner.
SimplexTemplateTagAssigner::SimplexTemplateTagAssigner( SimplexTemplateRefiner* r )
{
    this->mesh_refiner = r;
    this->tag_manager  = 0;
}

/// Empty destructor for good form.
SimplexTemplateTagAssigner::~SimplexTemplateTagAssigner() {}

/**\brief Given endpoint coordinates and tag values plus midpoint coordinates, compute midpoint tag
 * values.
 *
 * Normally, this function will be invoked by the EntityRefiner before evaluate_edge is called.
 * However, if evaluate_edge() changes the parametric coordinates of the midpoint,
 * it should call evaluate_tags_at_midpoint() again to update any tag values;
 * that is why this function is a member of EdgeSizeEvaluator and not EntityRefiner.
 *
 * @param[in] c0 Pointer to endpoint 0 coordinates. The parametric coordinates (3) are followed by
 * world coordinates (3).
 * @param[in] t0 Pointer to endpoint 0 tag values.
 * @param[in] cm Pointer to midpoint coordinates. The parametric coordinates (3) are followed by
 * world coordinates (3).
 * @param[out] tm Pointer to midpoint tag values.
 * @param[in] c1 Pointer to endpoint 1 coordinates. The parametric coordinates (3) are followed by
 * world coordinates (3).
 * @param[in] t1 Pointer to endpoint 1 tag values.
 */
void SimplexTemplateTagAssigner::operator()( const double* c0,
                                             const void* t0,
                                             EntityHandle h0,
                                             const double* cm,
                                             void* tm,
                                             const double* c1,
                                             const void* t1,
                                             EntityHandle h1 )
{
    double c0m_squared = 0.;
    double c01_squared = 0.;
    for( int i = 0; i < 3; ++i )
    {
        double tmp = cm[i] - c0[i];
        c0m_squared += tmp * tmp;
        tmp = c1[i] - c0[i];
        c01_squared += tmp * tmp;
    }
    double lambda           = sqrt( c0m_squared / c01_squared );
    double one_minus_lambda = 1. - lambda;

    DataType data_type;
    int tag_size;
    int num_components;
    int num_tags = this->tag_manager->get_number_of_vertex_tags();
    Tag tag_handle;
    int tag_offset;
    for( int i = 0; i < num_tags; ++i )
    {
        this->tag_manager->get_input_vertex_tag( i, tag_handle, tag_offset );
        this->tag_manager->get_input_mesh()->tag_get_data_type( tag_handle, data_type );
        this->tag_manager->get_input_mesh()->tag_get_bytes( tag_handle, tag_size );

        switch( data_type )
        {
            case MB_TYPE_DOUBLE: {
                num_components = tag_size / sizeof( double );
                double* t0i    = (double*)( (char*)t0 + tag_offset );
                double* tmi    = (double*)( (char*)tm + tag_offset );
                double* t1i    = (double*)( (char*)t1 + tag_offset );
                for( int j = 0; j < num_components; ++j )
                    tmi[j] = one_minus_lambda * t0i[j] + lambda * t1i[j];
            }
            break;
            default:
                memcpy( (char*)tm + tag_offset, (char*)( h0 < h1 ? t0 : t1 ) + tag_offset, tag_size );
                break;
        }
    }
}

void SimplexTemplateTagAssigner::operator()( const void* t0, const void* t1, const void* t2, void* tp )
{
    (void)t0;
    (void)t1;
    (void)t2;
    (void)tp;
}

void SimplexTemplateTagAssigner::set_tag_manager( RefinerTagManager* tmgr )
{
    this->tag_manager = tmgr;
}

}  // namespace moab
